From owner-freebsd-stable@FreeBSD.ORG Tue Jun 1 15:47:05 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 25EE31065676 for ; Tue, 1 Jun 2010 15:47:05 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id EBCFB8FC13 for ; Tue, 1 Jun 2010 15:47:04 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id A807246C08; Tue, 1 Jun 2010 11:47:04 -0400 (EDT) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPA id 916F18A026; Tue, 1 Jun 2010 11:47:03 -0400 (EDT) From: John Baldwin To: Jeremy Chadwick Date: Tue, 1 Jun 2010 10:20:01 -0400 User-Agent: KMail/1.12.1 (FreeBSD/7.3-CBSD-20100217; KDE/4.3.1; amd64; ; ) References: <201005272348.o4RNmgWh014243@hugeraid.jetcafe.org> <201005311825.o4VIPp5F051573@hugeraid.jetcafe.org> <20100531184525.GA89545@icarus.home.lan> In-Reply-To: <20100531184525.GA89545@icarus.home.lan> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201006011020.01318.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Tue, 01 Jun 2010 11:47:03 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95.1 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.5 required=4.2 tests=AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: Garrett Cooper , freebsd-stable@freebsd.org, Clifton Royston Subject: Re: Locking a file backed mdconfig into memory X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Jun 2010 15:47:05 -0000 On Monday 31 May 2010 2:45:25 pm Jeremy Chadwick wrote: > On Mon, May 31, 2010 at 11:25:51AM -0700, Dave Hayes wrote: > > Jeremy Chadwick writes: > > > Is the mfsroot file compressed (.gz extension)? Reason I ask is that > > > the OP states he's using RELENG_7... > > > > Yes it is compressed. > > > > > http://jdc.parodius.com/freebsd/pxeboot_serial_install_7.html#step7 > > > > Thanks much for this. I did a simple test, I rebuilt a DVD that wasn't > > booting to use a lower level of compression (gzip -9 to gzip -6) on > > mfsroot without changing anything else. This caused it to boot normally. > > > > I'm not sure it's conclusive evidence, but it certainly looks like a > > weak datapoint supporting this kernel bug being the source of my > > problem. > > > > Is this problem fixed in 8.0 or by a patch? > > With regards to said bug, gzip compression seems to work fine on > RELENG_8, at least in my experiences: > > http://jdc.parodius.com/freebsd/pxeboot_serial_install_8.html > > I'm not sure the level of compression is what triggers the bug though; > I haven't tested all levels (1 through 9). > > CC'ing jhb@ since he last updated PR kern/120127 (which I would say is > still a problem on RELENG_7 :-) ). John, are you aware of any gzip > decompression / mfsroot changes which might explain the problem on > RELENG_7? I haven't done a "thorough" series of tests, but on my > testbed boxes RELENG_8 works fine with a gzip'd mfsroot. Ok, if you are using a stock mfsroot from a release build, that should work fine. If you have built a custom mfsroot that is larger, then you may need to increase NKPT on i386. In very recent 7 and later you can do this by setting it to a new value in your kernel config. In older versions you can do this by manually adding a #define to set a new value of NKPT in opt_global.h or hacking on the source directly. -- John Baldwin